At a restaurant Mike and his three friends that means that there was four people splitting the bill. If each of them paid $13 then the bill was $52
4 * 13 = $52
Every year, the price of the smartphone is the 
of the price of the previous year (since we lose the 
, we remain with the ).
Since can be written as 
, the price after one year will be
After two years, the price is the of the price after one year:
And so on: after three years we have
So, the answer is somewhere between three and four years.
Bakabaga anabahakan agajaba Avanavajakab
-4.2c+4.8d is the answer to this equation.
